(1) Field of the Invention
This invention relates to an improved process for recovering argon from gaseous streams, and more particularly to an improved process for recovering argon from a gaseous stream remaining after the recovery of hydrogen values from an ammonia synthesis gas.
(2) Description of the Prior Art
In U.S. Pat. No. 4,338,108 to Isalski et al., there is disclosed a process for recovery of argon from a gaseous stream remaining after the recovery of hydrogen from an ammonia synthesis gas. In accordance with such process, the tail gas is initially fractionated to provide a substantially hydrogen-free liquid stream comprised of argon, methane and nitrogen which is expanded into a first fractionation column to form an overhead gaseous stream including argon. The argon-nitrogen stream is thereupon introduced into a second fractionation column to form product argon withdrawn as liquid bottoms from the second fractionation column. Such process has excessive equipment requirements to provide for the separation of residual hydrogen as well as excessive power requirements per unit volume of liquid product argon.